In the field of food products, the storage of palletized loads is very frequently carried out automatically at the end of the manufacturing places.
In the case of standard pallets, which constitute 90% of the pallets reused in recycle throughout the world, the cohesion between the load and the pallet is provided by a film secured beneath the lower deck of the pallet, and, while pallets are being manipulated, the forks of the handling equipment penetrate the entry slots of the pallet, perforating, or tearing, the plastic film, thus resulting in a weakening or destruction of the bond between the pallet and the palletized lead.
In addition, the storage of palletized loads in racks, in several rows and on several levels, is generally carried out by handling robots which are equipped with forks identical to those of fork-lift trucks. The automation of the insertion of the forks into the pallet requires the monitoring, by means of photoelectric cells, of the passage between the sliding supports or skis.
The presence of an exterior packaging film, generally made of polyethylene, around the palletized load disturbs this monitoring and it is desirable for the position of the exterior packaging film to be reproducible.